When no permission to draw a graph... it would be better to return an ERROR IMAGE rather than ERROR text...

I am on a page... looking at a users stats...

http://www.tbshs.herts.sch.uk/moodle/course/user.php?id=1&user=511&mode=stats

And there is an embedded graph. Which is something like: <img src="http://www.tbshs.herts.sch.uk/moodle/course/report/stats/graph.php?mode=2&course=1&time=32&report=10&userid=511">

Some users do not have permission to run the graph... and that is fine... but since the source for errors would show something like: <img src"=you do not have permission message.."> it shows an drawable image error.

Is it better... that if you do not have permission to run "http://www.tbshs.herts.sch.uk/moodle/course/user.php?id=1&user=511&mode=stats" that it returns an IMAGE saying you do not have permission... in the same way that it returns the Graph Image when you do have permission. This means <img src=....> is not ruined.